JPH08285012A - Torque variation absorbing damper - Google Patents

Abstract

PURPOSE: To realize a whirl-stop action even without a whirl-stop pin thereby reduce the number of a part item while having a function same as in a case wherein the stop pin is provided, by providing a recessed part, wherein a bearing is fitted to be engaged in a diameter direction, on the inner peripheral surface of a pulley. CONSTITUTION: In a torque variation absorbing damper, since a resin-made bearing 5 is fitted to be engaged in a diameter direction with a recessed part 5c provided on the inner peripheral surface of a pulley 5, the whirl-stop between the pulley 5 and the bearing 9 is performed. Consequently, a whirl-stop action can be made without a whirl-stop pin. Also when the resin-made bearing 9 is thermally expanded, resin 9a is increasingly entered into the recessed part to absorb an expanded part by a certain degree. Consequently, the excessive increase of slide resistance can be eliminated at the time of the thermal expansion of the bearing 9, thereby preventing the hindrance to a necessary slide rotation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention absorbs torque fluctuations that occur on the crankshaft side when transmitting torque from an engine crankshaft to various auxiliary machines via an endless belt, and the endless belt side. The present invention relates to a torque fluctuation absorbing damper that smoothly rotates an endless belt or an auxiliary device without transmitting the torque.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG.
A torque fluctuation absorbing damper is known in which a pulley 23 is connected to the outer peripheral side of the pulley via a coupling rubber 22 and a resin bearing 24 is arranged on the inner peripheral side of the pulley 23 (actually developed 63-68540). (See the official gazette).

However, in this torque fluctuation absorbing damper, the inner peripheral surface of the bearing 24 and the outer peripheral surface of the hub 21 sliding therewith, and the outer peripheral surface of the bearing 24 and the inner peripheral surface of the pulley 23 sliding therewith. Since they are all formed into a completely smooth surface, they tend to slip too much, which may cause problems such as the coupling rubber 22 being excessively twisted in the rotational direction. Therefore, conventionally, a plurality of detent pins (not shown) are press-fitted from one side in the axial direction between the bearing 24 and the hub 21 in an evenly distributed manner so as to deter the detent. Then, there is a problem that the number of parts of the damper is increased because the anti-rotation pin is required. In the conventional torque fluctuation absorbing damper described above, no measures are taken against the fact that the resin bearing 24 thermally expands due to sliding heat generation or the like, and the sliding resistance increases due to this. Therefore, according to the above-described conventional torque fluctuation absorbing damper, there is a problem that the sliding resistance becomes too large at the time of thermal expansion of the bearing 24 and the required sliding rotation is hindered.

[0004]

SUMMARY OF THE INVENTION In view of the above points, the present invention is capable of exerting a detent action even without a detent pin, and thus has the same function as when the detent pin is provided. However, it is an object of the present invention to provide a torque fluctuation absorbing damper that can reduce the number of parts. At the same time, it is an object of the present invention to provide a torque fluctuation absorbing damper in which the sliding resistance does not become excessively large during thermal expansion of the resin bearing and the required sliding rotation is not hindered. .

[0005]

In order to achieve the above object, a torque fluctuation absorbing damper of the present invention has a hub connected to a pulley via a coupling rubber and a resin formed on the inner peripheral side of the pulley. In the torque fluctuation absorbing damper in which the above bearing is arranged, the inner peripheral surface of the pulley is provided with a recess in which the bearing fits and engages in the radial direction.

[0006]

In the torque fluctuation absorbing damper of the present invention having the above structure, the resin bearing is press-fitted into the inner peripheral side of the pulley from one side in the axial direction, and the excess resin is inserted into the concave portion, so that the bearing is inserted into the concave portion. Fit and engage in the radial direction. Excess resin is created by setting the press-fit margin. Further, when the bearing made of resin thermally expands, the resin more and more enters the concave portion and absorbs the expanded amount to some extent.

[0007]

Embodiments of the present invention will now be described with reference to the drawings.

As shown in FIGS. 1 and 2, a first sleeve 2 is fitted on the outer peripheral side of a hub 1 having a substantially L-shaped cross section, and a coupling rubber 3 is attached on the outer peripheral side of the first sleeve 2.
The second sleeve 4 is connected via the second sleeve 4, and the pulley 5 having the pulley grooves 5a and 5b is fitted on the outer peripheral side of the second sleeve 4. Further, the third sleeve 6 is provided on the outer peripheral side of the hub 1.
And a mass body (also referred to as a vibrating ring) 8 is connected to the outer peripheral side of the third sleeve 6 via an elastic body 7 made of a rubber-like elastic material, and the mass body 8 is located on the inner peripheral side of the pulley 5. And a resin bearing 9 having a substantially L-shaped cross section is interposed between the mass body 8 and the pulley 5. Further, a predetermined number of key groove-shaped recesses 5c are provided on the inner peripheral surface of the pulley 5 in the outer peripheral side of the bearing 9, and the recesses 5c are equally distributed (for example, four equally distributed). The bearing 9 is press-fitted from one side, and the excess resin 9a is removed by the recess 5
The bearing 9 fits into the recess 5c and is engaged in the radial direction by entering into c. The extra resin 9a is created by setting the press-fitting margin, that is, by setting the outer diameter of the press-fitting portion of the bearing 9 to be slightly larger than the inner diameter of the press-fitting portion of the pulley 5. Further, the recess 5c is formed to a certain depth, so that when the resin bearing 9 thermally expands, the resin 9a further enters the recess 5c and can absorb the expansion to some extent. ing. Each of the parts has an annular shape, and the coupling rubber 3 is vulcanized and adhered to the first and second sleeves 2 and 4,
The elastic body 7 is vulcanized and adhered to the third sleeve 6 and the mass body 8.

The torque fluctuation absorbing damper having the above structure is fixed to a crankshaft (not shown) by the hub 1 and an endless belt (not shown) is wound around each pulley groove 5a, 5b of the pulley 5. When transmitting torque from the crankshaft to various auxiliaries via the damper and the endless belt, the torque fluctuation generated on the crankshaft side is not absorbed and transmitted to the endless belt side, and the endless belt or the auxiliary machine Rotate smoothly. Further, a torsional damper portion composed of the elastic body 6 and the mass body 7 constitutes a resonance system to absorb and suppress the torsional vibration generated on the crankshaft side.

In the torque fluctuation absorbing damper having the above structure, since the resin bearing 5 is fitted in the recess 5c provided in the inner peripheral surface of the pulley 5 and engaged in the radial direction,
As a result, the pulley 5 and the bearing 9 are prevented from rotating. Therefore, it is possible to achieve the anti-rotation action without the anti-rotation pin as in the conventional case, and it is possible to reduce the number of parts while having the same function as in the case where the anti-rotation pin is provided. Resin bearing 9
When is thermally expanded, the resin 9a more and more enters the concave portion and absorbs the expanded amount to some extent. Therefore, the sliding resistance does not become too large when the resin bearing 9 is thermally expanded, and it is possible to prevent the required sliding rotation from being obstructed.

In the above embodiment, a key groove-shaped recess 5c is provided on the inner peripheral surface of the pulley 5. However, the recess 5c has a shape in which the resin bearing 5 is fitted and is engaged in the radial direction. There is no particular limitation as long as it matches. FIG. 3 shows a spline-shaped recess 5c as an example. In the above embodiment, the mass body 8 is arranged on the inner peripheral side of the bearing 9, but instead of the mass body 8, as shown in FIG.
A hub may be arranged. Further, in the above-described embodiment, the bearing 9 is formed in a substantially L-shaped cross section, but the bearing 9 may be a simple cylindrical body as shown in FIG. Further, as shown in the figure, when the required number of slits 9b are provided on the resin bearing 9, the slits 9b can suppress the thermal expansion in the inner diameter direction or the circumferential direction.

[0012]

The present invention has the following effects.

That is, in the torque fluctuation absorbing damper of the present invention having the above structure, since the resin bearing is fitted in the concave portion provided on the inner peripheral surface of the pulley and engaged in the radial direction, This prevents the pulley and the bearing from rotating. Therefore, it is possible to achieve the anti-rotation action without the anti-rotation pin as in the conventional case, and it is possible to reduce the number of parts while having the same function as in the case where the anti-rotation pin is provided. Further, when the resin bearing thermally expands, the resin more and more enters the concave portion and absorbs the expansion to some extent. Therefore, the sliding resistance does not become too large during thermal expansion of the resin bearing, and it is possible to prevent obstruction of the required sliding rotation.

[Brief description of drawings]

FIG. 1 is a half cutaway view of a torque fluctuation absorbing damper according to an embodiment of the present invention.

FIG. 2 is an enlarged view of the direction of arrow A in FIG.

FIG. 3 is a cross-sectional view of a main portion of a torque fluctuation absorbing damper showing another example of a recess.

FIG. 4 is a perspective view of a bearing

FIG. 5 is a half sectional view of a torque fluctuation absorbing damper according to a conventional example.

[Explanation of symbols]

 1 Hub 2, 4, 6 Sleeve 3 Coupling Rubber 5 Pulleys 5a, 5b Pulley Groove 5c Recess 7 Elastic Body 8 Mass Body 9 Bearing 9a Resin 9b Slit

Claims (1)

[Claims] 1. A torque fluctuation absorbing damper in which a pulley 5 is connected to the outer peripheral side of a hub 1 via a coupling rubber 3 and a resin bearing 9 is arranged on the inner peripheral side of the pulley 5, A torque fluctuation absorbing damper characterized in that a recess 5c is provided on the inner peripheral surface of the bearing 9 to engage with the bearing 9 in the radial direction.